Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c618d0f710344fe…

MALICIOUS

PDF

87.0 KB Created: 2021-07-17 05:25:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: 6cbde5d36113042d78b280ebd58abd5a SHA-1: 0c481e7bb7c14eba28b9a92ae55adf3b0c67198e SHA-256: 3c618d0f710344fe0d26be432c0263e2503426e781878d0c5e189148238e5ec4
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample contains embedded JavaScript, which is a common technique for executing malicious code within PDFs. It also features a link farm pointing to numerous distinct hosts, many of which appear to be compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the final destination and evade detection. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://doellefjelde-mussemarked.dk/images/newsmail/file/52250215564.pdf In PDF document text
    • https://perfecthospitals.org/FCKeditor/file/32106392745.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/79e219e17ff30b0565514a683641bd26/6850878016.pdfIn PDF document text
    • http://grandrosso.com/js/upload/files/xemafaradudox.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160c48651d7964---86473074931.pdfIn PDF document text
    • http://kirks-pool.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c70dcbb2f0---rizuvilofisipeviru.pdfIn PDF document text
    • http://freeski.hu/freeski/file/32677962748.pdfIn PDF document text
    • http://skoleniridicu-online.eu/ckfinder/userfiles/files/73859607540.pdfIn PDF document text
    • http://tcihk.com/userfiles/gitebufovutesedodimuk.pdfIn PDF document text
    • https://mygamedaysports.com/wp-content/plugins/super-forms/uploads/php/files/ac18106744a6a0d3019ab13002add550/33054892936.pdfIn PDF document text
    • https://ankaratemizlikcim.com/depo/sayfaresim/file/sunuvufona.pdfIn PDF document text
    • https://kachhiproperties.com/wp-content/plugins/super-forms/uploads/php/files/m053l1j4cvogs18krh5vi726q7/soxad.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/vaadmekpj1korqs5k87h7o1268/4054379703.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c437b40e021---xepigubozikunu.pdfIn PDF document text
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160e7908c477c3---3122879042.pdfIn PDF document text
    • http://btc-ltd.com/upload/file/48073037052.pdfIn PDF document text
    • https://www.onestopnaturalstore.ca/wp-content/plugins/super-forms/uploads/php/files/seqgamfddapg5f4r980bif0b9s/18475439561.pdfIn PDF document text
    • http://www.alfainstal.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16079a510dd2b3---83891868402.pdfIn PDF document text
    • https://gpuhub.net/wp-content/plugins/super-forms/uploads/php/files/sg7qp80v8kain84r8fqe8of33d/zigabuvasunidakopox.pdfIn PDF document text
    • https://hafa-verein.de/wp-content/plugins/super-forms/uploads/php/files/fe6c3495fe9df770443b2daa09de53b6/sedilax.pdfIn PDF document text
    • http://planbmedia.hufiles/11834539647.pdfIn PDF document text
    • https://ailani.org/wp-content/plugins/super-forms/uploads/php/files/24be3b34c2a7afe98a6846badf4a062f/kunek.pdfIn PDF document text
    • https://drahmetbostanci.com/wp-content/plugins/formcraft/file-upload/server/content/files/160942ce983f65---45272544519.pdfIn PDF document text
    • https://babetravelling.com/ckfinder/userfiles2/files/49788391523.pdfIn PDF document text
    • https://hps-gruppe.com/wp-content/plugins/super-forms/uploads/php/files/5d7f75su6i53idhraa7di14bf8/86132278070.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=calculate+cost+of+house+constructionPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f470.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF470 16332 bytes
SHA-256: 63451a72f5a4ef0fc0a11bf4b0cece81a5049febbac4080362a4bdccaa98fd1b
font_01_sfnt_off00011e85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E85 10564 bytes
SHA-256: 3068c762f4e63f1e15d2eab21575d9a82fe4969acd49f1a2b07020a48422c5e2
font_02_sfnt_off00013696.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13696 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1